Ore and stone jaw crushing machines



May 8, 1962 F. w. BRADWELL 3,033,476

ORE AND STONE JAW CRUSHING MACHINES Filed Nov. 8, 1960 2 Sheets-Sheet 2 B wmfi z, 141M411 WM Attorneys nitel Stats This invention relates to machines for crushing stone, ore and the like, and more particularly to crushing machines of the type in which a movable jaw is vibrated with respect to a fixed jaw by means of an eccentric, whether the eccentric carries a rocker arm bearing the movable jaw, or the movable jaw is mounted on a rocker arm connected by toggle plate mechanism to the eccentric.

Although an increase in the frequency of vibration of the movable jaw results in an increase in the crushing rate, alirnit to the output of the machine is reached when the jaws are opened for an insufficient time for the crushed material to fall under gravity, so that the machine becomes choked.

The object of the present invention is to provide a crushing machine in which the time that the jaws are opening and opened is increased beyond the 50% attainable out of the complete cycle time of a conventional machine of the type referred to.

According to the present invention, a crushing machine has a jaw movable with respect to a fixed jaw and adapted to be driven differentially by two eccentrics, with one of the eccentrics rotatable at twice the speed of the other and so phased with respect to the other eccentric that the jaws are maintained substantially fully open for a period between successive opening and closing movements of the movable jaw.

This result arises from the phasing causing the throws of the two eccentrics to be in conjunction at every other revolution of the faster eccentric (providing the fully closed position of the moving jaw) and in opposition at alternate revolutions of the faster eccentric (providing substantially the fully opened position of the movable jaw), and because the phasing also causes the throws to move rapidly out of conjunction after fully closed position, and similarly rapidly into conjunction before the next fully closed position. Thus, the combined period in which the jaws are opening and remain open consid erably exceeds the 50% attainable out of the complete cycle of time of a conventional machine driven by a single eccentric and, therefore the speed of the machine may be increased proportionally before the machine becomes choked. Also, as a consequence of the increased speed, in conjunction with the rapid movement of the eccentric throws in moving the movable jaw to fully closed position, the closing time is decreased, so that the impact of the movable jaw on the material to be crushed is increased, which makes the machine particularly suitable for crushing hard materials.

The eifective amount of movement between fully closed and fully open positions may be made substantially equal to the throw of the slower eccentric, so' that in effect the faster eccentric modifies the time/movement curve of the slower eccentric to shorten the time occupied by the closing and opening of the movable jaw. Preferably the throw of the slower eccentric is so much greater than the throw of the faster eccentric, e.g. twice that the combined opening and open period occupies substantially 75% of the cycle time between successive closed positions.

There being one opening movement in a complete cycle which in duration is equivalent to two complete cycles of the simple eccentric drive of a conventional machine, a machine according to the invention and having an eccentric ratio of 2:1 may be driven at 1 /2 times the speed of a conventional machine before choking occurs. Thus, the output may be increased by up to 50% of that of a conventional machine of similar dimensions. Although with this ratio between the eccentrics a slight partial re closing of the jaws will occur, during the open period, owing to precession of the eccentrics relative to each other this is not considered detrimental since it will produce a slight vibration of the movable jaw whilst in open position, which vibration will assist in discouraging any tendency to choking during the downward movement of the material undergoing crushing.

One eccentric may be mounted on the other, the latter rotatable as a shaft, with a common driving shaft connected to the respective eccentrics by two pairs of pinions of such respective ratios that'one eccentric is rotated at twice the speed of the other. By carryingeccentrically on the driving shaft the pinion that serves to drive the eccentric that is mounted on the other eccentric, and with the pinion equalling the eccentricity of that other eccentric, circular pinions may be used for the eccentrically carried pinion and the pinion with which it meshes, in spite of the eccentric motion imparted to the driven pinion of the pair. Consequently, with the mere provision of one pinion being carried eccentrically on the driving shaft, two pairs of circular pinions suiiice for the driving of the two eccentrics at the required 2:1 difference of speed.

The eccentric mounted on the other eccentric serves to operate directly a rocker arm bearing the movable jaw, or a rocker arm that moves that jaw through toggle mechanism.

The invention will now be further described with reference to the accompanying drawings, in which-- FIGURES 1 to 8 are diagrams of jaw movements and of eccentric drives by which those movements are produced, the amplitudes of the curves in FIGURES l, 3, 5 and 7 being shown to a greater scale than the eccentricities in FIGURES 2, 4, 6 and 8 that produce these amplitudes,

FIGURES 1 and 2 relating to the usual form of single eccentric drive, FIGURES 3 and 4 and FIGURES 5 and 6 relating to the individual effects of two eccentric drives of different throw and frequency, and FIGURES 7 and 8 relating to the combined effect of these two eccentric drives as combined in carrying out the invention;

FIGURE 9 is a part-sectional side elevation of one form of crusher using the combined eccentric drive;

FIGURE 10' is a plan of FIGURE 9; and

FIGURE 11 is a part-sectional side elevation of another form of crusher using the combined eccentric drive.

In FIGURE 1, the curve 1 shows the amplitude 2 of movement resulting in the moving jaw of a crusher ac tuated by a single eccentric 3 (FiGURE 2) of eccentricity 4, the movement of this amplitude (or throw, amounting to twice the eccentricity) taking place once in each revolution. The effect through two successive revolutions OI-II is shown in FIGURE 1.

. In FIGURE 3, the curve 5 resembles the curve 1 of FIGURE 1, but has a reduced amplitude (or throw) 6 because of its production by an eccentric 7 (FIGURE 4) of correspondingly less eccentricity 8. Again, the etfect through two successive revolutions OI--II is shown in FIGURE 3.

In FIGURE 5, the curve 9 of amplitude (or throw) 10 is produced by an eccentric 11 (FIGURE 6) of eccentricity 12 approximately twice the eccentricity of 8 of the eccentric 7 and rotating at one-half the speed of the eccentric 7. Consequently, when the eccentric 7 has made one revolution, the eccentric 11 has made one-half revolution only, O-I--II in FIGURE 5 now representing one essence full revolution or cycle of the eccentric 11 whilst the eccentric 7 is making two successive revolutions or cycles. In consequence, the throws of the eccentrics 7, 11 are sometimes in conjunction and sometimes in opposition, with the result that, as shown by the curve 13 in FIGURE 7, some 75% of the duration of two complete cycles of the eccentric 7 of smaller eccentricity is occupied by first a resultant rapid opening movement A-B, and second a substantial maintenance of the resultant opening B C, C-D, leaving some 25% only for the resultant rapid closing movement DE. The total amplitude 10A between open and closed remains much the same as the amplitude 10" due to the eccentric 11 (FIGURES and 6).

FIGURE 8 shows at (a) (e) the relative positions of the eccentrics 7, 11 corresponding to the positions A E of FIGURE 7, from which it will be seen that at C, i.e., halfway through the complete cycle AE of the operation of the two eccentrics, the eccentrics are in opposition, with the result that at 13A there is a partial re-closing movement between positions 135 of mam'mum opening movement that arise just before and just after the eccentrics occupy the relative positions of FIGUlsES 8(1)) and 8((1) respectively.

As compared, therefore, with the operation of a conventional single eccentric, as FIGURES l and 2, with the crusher jaws opening and open for only 50% of each cycle, O-I, III, the combined use of eccentrics as in FIGURES 3 to 6 results in the jaws undergoing opening and remaining open for 75% of each cycle OIl. Each cycle O-II may thus be performed some 50% faster than each cycle O-l or L 11, i.e. the larger throw eccentric 11 of the combination 7, 11 may be driven some 50% faster than the conventional single eccentric 3, the smaller throw eccentric '7 of the combination being of course driven at twice the speed of the eccentric 11. (It is to be noted that the longitudinal scales of FIGURE 1 and of FIGURES 3, 5, and 7 do not attempt to relate the the relative rates of operation of the conventional single eccentric and of the combined eccentrics according to the invention: to do this, the dimension O-II in FIGURES 3, 5, and 7 would have to be reduced to two-thirds of either dimension OI or III in FIGURE 1).

The movement imparted to the movable jaw of a crusher by the combined eccentrics 7, 11 is such that, after the crushing blow has been strucl; by the closing movement ending at A in FIGURE 7, the jaw rapidly opens to 13B, and crushed material descends by gravity in the space between the jaws. The movable jaw then effects the partial closing movement at 13A before receding to the second fully open position 1313, the result of this being to discourage choking by displacing the crushed pieces from any interlocking positions they may assume during their descent by gravity. Thus, the combined eccentrics not only make available a bigger proportion of the faster cycle OII during which the proportionately greater throughput of material may descend between the jaws: they also impart a vibration to encourage that descent.

FIGURES 9 and 10 and FIGURE 11 show respectively two applications of the above-described combination of eccentrics to the two well-known types of machine in which the movable jaw is directly driven at the pivot from which it depends, and in which the movable jaw simply depends from a pivot and is indirectly driven from a rocker arm or pitman that is driven at the pivot from which it itself depends, the rocker arm operating two toggle plates, one of which bear on the frame of the machine and the other on the movable jaw.

In FIGURES 9 and 10, a movable jaw 14, with jaw plate 14A, is urged away from a frame plate 15, with a plate 15A forming a fixed jaw, by a tension rod 16 and spring 17 to keep the jaw 14 in bearing with one end of a toggle plate 18, the other end of which bears on a rear plate 19 of the frame of the crusher. A driving pulley 20 on a shaft 21 journalled in and extending between the side plates 22 (one only shown) of the frame serves to drive two gears 23, 24 secured to the shaft and meshing respectively with gears 25, 26, such that the gear ratio 23:25 is twice the gear ratio of 24:26, the ratio between the gears 23, 25 being 121. The gear 25 is thus driven at twice the speed of the gear 26. The gear 25 'rotates a shaft 28 journalled on the side plate '22, this shaft being eccentric over its length 29 extending across the frame, to constitute one of the eccentrics participating in the drive of the movable jaw 14. The eccentric length 29 carries an eccentric sleeve 30 connected to the gear 26. This sleeve 30 constitutes the other eccentric for driving the jaw 14. The gear 24 that meshes with the gear 26 is mounted, as shown at 31, on the drive shaft 21, with an eccentricity equal to and in phase with the eccentric length 29 of the shaft 28, such that as the maximum throw of the gear 24 is towards the shaft 28, the throw of the eccentric length 29 has moved the gear 26 correspondingly awayfrom the shaft 21. The axes of the gears 24, 26 thus remain separated by a constant horizontal distance, so that the gears always remain in mesh. The actual distance between these two axes varies slightly at different positions in the relative rotations of the gears 24, 26, because of the vertical components of the eccentric movements, but not sufficiently to affect materially the meshing ofthe gears, which thus can be truly circular gears. However, the profiles of either or both of the gears 24, 26 could depart sufficiently from the circular to compensate fully for the slight variation that occurs in the distance between the axes.

The eccentric sleeve 30 carries a sheave 32, which forms with the movable jaw 14 a pitman or rocker arm by which that jaw is moved relatively to the fixed jaw 15 about an end of the toggle plate 18 as a pivot. The eccentric length 29 of the shaft 28 corresponds to the eccentric 7 of FIGURES 3 and 4 performing t-wo revolutions for each revolution of the eccentric sleeve 30, come sponding to the eccentric 11 of FIGURES 5 and 6. The movable jaw 14 thus performs a movement corresponding to the curve 13 of FIGURE 7.

The combined maximum throws of the eccentric length 29 and the eccentric sleeve 30 are in a plane that includes the axes of the parallel shafts 21, 28, i.e., in the approximately horizontal direction of movement of any part of the jaw plate 14A with respect to the jaw plate 15A.

In FIGURE 11, a movable jaw 33, suspended at 34-, is moved with respect to a fixed jaw 35 by a rocker arm 36 operating between two toggle plates 37 and integral with an eccentric sheave 38 corresponding to the sheave 32 of FIGURES 9 and 10. Similar fixed shafts, gears, and eccentric shaft are used (the same reference numerals as in FIGURES 9 and 10 being employed), but the combined maximum throw of the eccentric length 29 of the shaft 28 and the eccentric sleeve 30 are in a vertical plane through the axis of the shaft 28, this movement being transferred by the rocker arm 36 and the toggle plates 37 into the desired generally horizontal movement of the jaw 33. I

What I claim is:

1. Ore and stone crushing machine comprising a fixed jaw and a movable jaw, together with a pivot suspension for the movable jaw and jaw-moving means in operative connection with the movable jaw to swing it about the pivot suspension towards and away from the fixed jaw, the jaw-moving means including an inner eccentric and an outer eccentric mounted on and rotatable about the inner eccentric, means for driving the second eccentric, and means for driving the inner eccentric at twice the speed of the outer eccentric.

2. Ore and stone crushing machine comprising a fixed jaw and a movable jaw, a pivot suspension for the movable jaw, an inner eccentric in the pivot suspension, an outer eccentric mounted on and rotatable about the inner eccentric, means for driving the second eccentric, and means for driving the inner eccentric at twice the speed of the outer eccentric.

3. Ore and stone crushing machine comprising a fixed jaw and a movable jaw, together with a pivot suspension for the movable jaw, a rocker arm in operative connection with the movable jaw to swing it towards and away from the fixed jaw, a pivot suspension for the rocker arm, a first eccentric in the pivot suspension for the rocker arm, an outer eccentric mounted on and rotatable about the inner eccentric, means for driving the second eccentric, and means for driving the inner eccentric at twice the speed of the outer eccentric.

4. Ore and stone crushing machine comprising a fixed jaw, a movable jaw, a transverse pivot suspension for the movable jaw, an inner eccentric in the pivot suspension, a first pinion secured to the inner eccentric, an outer eccentric mounted on and rotatable about the inner eccentric, a second pinion secured to the outer eccentric, a transverse driving shaft, and two pinions secured to the driving shaft and meshing constantly with the pinions secured to the inner and outer eccentrics respectively, the driving ratio between the pinion meshing with the first pin-ion and that first pinion being twice the driving ratio between the pinion meshing with the second pinion and that second pinion.

5. Ore and stone crushing machine as in claim 4, comprising an eccentric mounting on the driving shaft of the pinion that meshes with the first pinion, the eccentricity of that mounting being equal to and in phase with that of the inner eccentric and the two pinions each being circular and maintained in constant mesh by the equal eccentricity and the phasing of the pinion mounting on the driving shaft and of the inner eccentric.

6. Ore and stone crushing machine comprising a fixed jaw, a movable jaw, a transverse pivot suspension for the movable jaw, a second transverse pivot connection, a rocker arm mounted to rock about the second suspension, an inner eccentric in the second suspension, a first pinion secured to the inner eccentric, an outer eccentric mounted on and rotatable about the inner eccentric, a second pinion secured to the outer eccentric, a transverse driving shaft, and two pinions secured to the driving shaft and meshing constantly with the pinions secured to the inner and outer eccentrics respectively, the driving ratio between the pinion meshing with the first pinion and that first pinion being twice the driving ratio between the pinion meshing with the second pinion and that second pinion, and connecting means between the rocker arm and the movable jaw.

7. Ore and stone crushing machine as in claim 6, comprising an eccentric mounting on the driving shaft of the pinion that meshes with the first pinion, the eccentricity of that mounting being equal to and in phase with that of the inner eccentric and the two pinions each being circular and maintained in constant mesh by the equal eccentricity and the phasing of the pinion mounting on the driving shaft and of the inner eccentric.

References Cited in the file of this patent UNITED STATES PATENTS 393,440 Low Nov. 27, 1888 548,179 Bunnell Oct. 22, 1895 578,357 Pfouts Mar. 9, 1897 962,998 Christ et a1 June 28, 1910 965,830 Mitchell July 26, 1910 2,257,388 Krider Sept. 30, 1941 2,605,051 Bogie July 29, 1952 

